I'm a new member of the list, but I'm reading the posts since January. I'm addicted...
If we have a large COP (10-100), I believe we can use thin film thermogenerators (http://en.wikipedia.org/wiki/Thermoelectricity) such as these http://www.micropelt.com/down/datasheet_mpg_d651_d751.pdf to make a self sustain wet cell... We can put thousands of those around a wet cell. They produce useful power with as little as 10 degrees Celsius (see datasheet). Cheers, Alberto.
